Quiz

1.	What is an interface?
2.	What is an interface diagram?
3.	Why is an interface used in a program?
4.	What is the difference between an interface and a user interface?
5.	Does the C programming language use interfaces?
6.	What kind of inheritance is similar to an interface?
7.	Can an interface be used with C++?
8.	Why do Java and C# support interfaces?
9.	What is a component?
10.	Give an example of a component.

Answers

1.	An interface specifies what a class must do, but not how it does it. It is syntactically similar to a class, but its methods are declared without any body. A class implements an interface by creating a complete set of methods defined by the interface.
2.	An interface diagram shows how a class can implement an interface.
3.	An interface is used in a program to enable similar classes to have a standard behavior while having the programmer who builds these classes define how the behavior is performed.
4.	The purpose of a user interface is to enable a user to use a program. An interface is a standard behavior. Programmers who use a class that implements an interface can expect that the class will define a set of standard methods. Programmers who build classes for use by other programmers must define a set of standard methods that conform to a standard interface.
5.	The C programming language doesn t use an interface because C is not an object-oriented programming language.
6.	An interface is similar to multiple inheritance.
7.	C++ does not support an interface, but it does support multiple inheritance.
8.	Java and C# support interfaces because they do not support multiple inheritance.
9.	A component is a class designed to fit into some preexisting class framework and may do so through inheritance or by implementing one or more interfaces. However, it must follow its environment s rules for components .
10.	An Integrated Development Environment is a good example because it enables programmers to drag and drop components such as buttons from a tool palette onto a form.